The invention concerns a pocket cage of synthetic material for roller bearings including a plurality of rollers spaced circumferentially, consisting of side rings and ribs arranged between them, with pocket-side working faces adapted to the roller shape, each rib having a first section situated in the region of the arc separating the rollers in the circumferential direction of the bearing and a second section holding the rollers in the radial direction of the bearing.
A cage of synthetic material for tapered roller bearings, whose pocket-side working faces hold the rollers apart and simultaneously hold them radially when no outer ring is provided, is already disclosed in DE 3,141,813. In this case the inner ring is usually provided with two rims, resulting in more difficult assembly. In the known embodiment the elasticity of synthetic material is utilized to slip the rollers over the rim of the inner ring until they assume their operational position in the pockets behind the rim. Since the rim usually is only roughly finished, damage to the surface of the rollers is unavoidable.
In order to avoid this disadvantage, DE 451,825 proposes to design the pocket wider in a partial region, in order to make it possible for the roller to be deflected radially upon assembly. However, this involves a thin-walled sheet-metal cage without a holding sections for the rollers, wherein these move within the said enlarged pocket section even in operation. This results in guidance on only a partial section of the roller length, owing to which the desired function of the cage is only partially fulfilled. It is therefore to be expected, rather, that the rollers will tilt and fail to maintain orderly travel geometry.